Durable shell for the battery holder: built for strength and longterm use, this holder shell is easy to solder and connect to your circuit, providing a reliable foundation for your project. 18650 battery compatibility: designed to hold standard 18650 cells, offering lightweight, portable support for these common lithiumion batteries. Simple, reliable metal spring: easy to install and connect, the metal spring ensures solid contact for circuit work and supports long service life. Battery storage box and protection: keeps 18650 batteries tidy and protected, helping prevent short circuits and loose connections during handling and use. Key benefits at a glance: Function: secure hold and reliable electrical contact for 18650 cells Compatibility: specifically designed for 18650 batteries Setup: easy to solder, connect, and install Durability: sturdy shell and durable spring for extended use Organization: keeps batteries orderly and safeguarded Practical use scenarios: DIY power supply or portable charger: assemble with PCB, connectors, and a shell to create a compact, replaceable power source. Prototyping electronics or robotics: use the holder to store spare 18650 cells for quick swaps during testing. Portable lighting or small devices: integrate into a device that requires removable, replaceable 18650 cells for easy maintenance.